In many integrated circuits, it is necessary to introduce delay in the propagation of some signal, or to slow the switching time of some signal. For example, delay may be introduced in input circuitry to allow for skew among input signals, or the input transition to a large driver, such as an output buffer, may be slowed so as to reduce sudden changes in current that would affect supply voltages.
Also, for most integrated circuit applications, the circuit must operate for some range of parameter, such as temperature or supply voltage, and the speed of transitions vary with these parameters. Then, when the deliberately introduced delay is designed to be adequate for the values of the variable parameters that give the fastest response, said deliberately introduced delay will be excessive for the values of the variable parameters that give the slowest response.
Accordingly, improvements which overcome any or all of the problems are presently desirable.